This invention relates to a metal sintered part, which is obtained from sintering metal powder and its production method.
The following method, referred to as tape automatic bonding (TAB), is utilized in semiconductor mounting technology. (i) Semiconductor chips are fixed on the carrier tape (long length film). They are placed at regular intervals along the edge side of the tape. (ii) The tape is traveled, and these semiconductor chips are conveyed in the manufacturing process. Simultaneously, wire bonding or similar bonding methods are utilized for each semiconductor chip.
This carrier tape is given momentum by the following process. (1) The wheel tooth of a sprocket gear engages with an aperture, which is created along the edges of the tape. (2) The turning sprocket gear moves the long length film. This sprocket gear has a ratchet gear, which (a) turns toward one direction, and (b) has multiple ratchet teeth in order to control the spinning amount (feeding amount).
These sprocket gear and ratchet gear are produced by a presswork method as separate framework components. Then, both frameworks are positioned and bound together with caulking. However, there are the following various deficiencies.
1) Many components are necessary, so the component logistical administration is complicated. Concurrent with this, the construction process is comprehensive.
2) For proper positioning, a concave part and a convex part are needed for the sprocket gear and the ratchet gear, in order to fit or inter-connect with each other, making the component configuration complicated.
3) Because of the low durability of the caulking (binding) parts and for other reasons, the reliability of the components cannot be maintained for a long term.
4) Ratchet teeth are easily worn out on the ratchet gear, so that a high degree of hardness (wear resistance) is required for the material quality. Therefore, a hardening process (using SK-4 material) is used for the produced ratchet gear. However, the hardening process causes distortion, causing a dimensional or tolerance error. In order to produce the ratchet gear within specifications, a subsequence process, such as grinding or similar process, is required after hardening. However, this results in an increase in the number of process stages and an increase in production cost.
Because of these defects and impediments, a new invention has been created. The objective of this invention is to offer a metal sintered part with the following characteristics and a production method which has:
(a) a high degree of hardness, and
(b) a superior wear resistance and (c) an uncomplicated production method.
1. A metal sintered part wherein the part is produced by de-binding and sintering a green body, which includes a metal powder and binding material. The above-mentioned metal powder is comprised of a self-fluxing alloy.
2. It is preferable that the above-mentioned self-fluxing alloy be a nickel radical self-fluxing alloy.
3. It is preferable that the above-mentioned green body be produced by using a metal powder injection molding method.
4. It is preferable that the content amount of the metal powder in the above-mentioned green body be between 80 and 98 wt %.
5. It is preferable that the Vickers hardness Hv on the surface of the above-mentioned metal sintered part be more than a value of 500.
6. It is preferable that the tensile strength of the above-mentioned metal sintered part be between 10 and 60 kg/mm2.
7. It is preferable that the metal sintered part have a portion designed for high wear durability.
8. It is preferable that the above-mentioned metal sintered part be a component within a power transmission.
9. It is preferable that the above-mentioned metal sintered part engage a first driveline (sprocket gear) and a second driveline (ratchet gear) in the power transmission component.
10. A production method of the metal sintered part wherein it includes the following three processes. (i) To produce a green body, which includes a metal powder and a binding material. The metal powder is comprised of self-fluxing alloy. (ii) To conduct a de-binding treatment on the obtained green body. (iii) To sinter the obtained de-binding part; then, to produce a metal sintered part.
11. It is preferable that the above-mentioned self-fluxing alloy be a nickel based self-fluxing alloy.
12. It is preferable that the production of the above-mentioned green body be conducted by using the metal powder injection molding method.
13. It is preferable that the content amount of the above-mentioned metal powder in the green body be between 80 and 98 wt %.